Typically, when manufacturing a cylinder block for use in a vehicle engine, a cylinder liner is provided on the inner circumference of each cylinder in a case where parts that slide against a piston need to have improved wear resistance. Cylinder liners are typically applied to cylinder blocks made of an aluminum alloy.
Known methods for manufacturing such cylinder blocks with cylinder liners include a method in which a cylinder liner is placed in a mold for a cylinder block before pouring a casting material into the mold.
Prior art cylinder liners for insert casting include the cylinder liners disclosed in Patent Document 1, Patent Document 2, and Patent Document 3.
[Patent Document 1] Japanese Examined Patent Publication No. 43-4842
[Patent Document 2] Japanese Patent No. 3253605
[Patent Document 3] Japanese Unexamined Patent Publication No. 2003-326353
(a) Patent Document 1 proposes a cylinder liner that has countless minute projections on the outer circumferential surface.
(b) Patent Document 2 proposes a cylinder liner of which the outer circumferential surface is formed to have a predetermined roughness.
(c) Patent Document 3 proposes a cylinder liner that has a number of projections on the outer circumferential surface, in which the projections each have a substantially conical undercut portion flaring outward and a flattened distal end.